1. Field of the Invention
The present invention relates to a defect inspection apparatus that detects defects (e.g., shorts and wire breaks) and foreign matter in an inspection target pattern, and more particularly to a defect inspection apparatus that includes a plurality of photoelectric image sensors as a detector.
2. Description of the Related Art
In general, conventional methods for raising the inspection speed of a defect inspection apparatus have been used to increase the speed of an image sensor, which is employed as a detector. For example, the speed of an image sensor has been increased by the use of a method that divides the output of an image sensor having a large inspection field of view or a large number of pixels into even-numbered pixels and odd-numbered pixels and output the resulting pixels in a parallel manner or by the use of a so-called multi-tap output method, which divides all pixels of an image sensor into a plurality of groups and outputs them in a parallel manner.
A known inspection apparatus disclosed, for instance, by JP-A-5-182887 uses a photoelectric image sensor as a detector. An inspection apparatus like this one uses a detector that includes a one- or two-dimensional array of photoelectric image sensors.